1. Field of the Invention
The invention relates to initiation of a program module corresponding to multiple versions.
2. Description of Related Art
An application program used for computers is upgraded when functions are added to the application program or to peripheral devices controlled by the application program. According to a conventional version upgrade, an old version of the program is once uninstalled and then a new version of the program is installed. Alternatively, the old-version program is executed under a new-version program (e.g., patent document 1).
[Patent Document 1]
JP-A No. 256212/2003
The related technology has been expected to improve the management of version compatibility among multiple program modules that cooperatively implement a specified function. That is, a specific application program can be easily upgraded using an installer and the like. However, it has been difficult to maintain the version compatibility when multiple program modules cooperate to necessitate the use of an application program, a peripheral device's driver program, and an intermediate program mediating between both programs.
For example, a peripheral device manufacturer may provide the driver program and the intermediate program. In such case, it is easy to maintain the version compatibility between both. However, there may be a case where the intermediate program mediates between processes of multiple application programs provided by multiple manufacturers. In such case, it is difficult to maintain the version compatibility. That is, it is difficult to request all application program manufacturers to change the application programs in accordance with revision of the driver program and the intermediate program. When a new version of the application program is used, a user needs to upgrade the versions of the driver program and the intermediate program. Otherwise, both are incompatible with each other. In this manner, programs may become unexecutable unless the version compatibility is maintained.